Representation of our membership is at the core of Local 399’s mission. From ensuring protection of prevailing wages to alleviating healthcare costs through coalition building, to improving our contractor and building partners competiveness, Local 399 has and will continue to work tirelessly toward the common interests of its members.

Founded in 1896, Local 399 today has nearly 10,000 members throughout Illinois and Indiana.

Local 399 is one of the largest and strongest local labor unions in the country. We offer classes and seminars at our new, state-of-the-art training facility designed to ensure that Local 399 members are the safest, most productive, highly skilled workers in the country.